Details in Designing a Net-Zero Energy Community

A few years ago, if a builder or developer announced the decision to establish a ZNE, or a Zero-net Energy Community, most of us would have thought it to be an experimental or unattainable concept. Today it’s not only becoming a reality, but turning into “the norm.” One community to aspire to such a goal is that of Liberty in West Sacramento, Calif. To attain this goal of ZNE, it takes the combined efforts of Land Owner (The Paik Family), Land Planning, City of West Sacramento Planning, Architecture, Landscape and Energy use and sourcing.

Early in the planning stages, many decisions were made to make it a smart community. Street orientation was one decision made early on and streets were designed in such a way as to give the community a more North/South orientation to take the most advantage of solar orientation.

The geographic location of Liberty is also advantageous to reducing energy costs for the homeowner. Nestled adjacent to the Sacramento River, residents will greatly benefit from the cool Delta breezes. These breezes can cool a home by as much as 10 or more degrees on warm afternoons, and as much as 50 degrees over the month of July, West Sacramento’s hottest month when temperatures can reach above 100 degrees.

Another highly effective and little known way of reducing energy costs was done though the conscious decision to maintain and preserve much of the indigenous old growth trees. The most obvious ways trees influence the local climate is by naturally lowering the air temperature through shade. But, trees also increase humidity, influence wind speed and reduce glare. Through a process called transpiration, the evaporation of water by large trees can produce the cooling effect of 10 room-sized air conditioners in a given day—and, when strategically placed, shade producing trees can help reduce homeowner cooling costs by as much as 30 percent.

In the winter months, these same trees help lower energy consumption by acting as natural barriers to wind that can put a large strain on heating systems. All of this forward thinking by land planning and landscape architecture/design help reduce energy consumption for the homeowner and thusly the community of Liberty as well. This, in turn, calls for less demand and less consumption therefore making the use of solar more efficient. All this combined makes the overall plan of a ZNE community much more attainable and realistic All of these efforts of the natural environment would be mute if the homes designed were not energyefficient as well.

Each home in Liberty will be designed to achieve zero-net energy, meaning that in the span of one year, each home will have a netenergy consumption cost of zero. This is achieved by a combined use of several different methods. Each home will be designed and equipped with smart appliances, which are highly efficient with a low demand on energy consumption. Energy-efficient and long lasting LED lighting, as well as energy-efficient HVAC systems, water heating systems and fresh air circulating systems will all be key factors in a zero-net energy home. In moving toward a cleaner environment, it is also the idea that each home is to be pre-wired for the addition of a charging station for those owning or hoping to purchase an electric vehicle.

To be a ZNE community, one needs to produce clean energy NOT supplied by an outside source/power grid. The use of solar panels will be the most obvious means to produce power for each home, therefore careful consideration of home orientation and roof design comes into play. With the goal to get the most efficient use out of the solar panels as you can, the roofs, when possible, will be designed and oriented in a way that takes as much solar exposure as possible.

Along with each home being equipped with their own solar panel system, the community of Liberty will also provide additional solar photovoltaic to produce energy for community infrastructure, such as community pedestrian and street lighting.

Finally, with major strides being made in energy storage/battery systems, the future certainly looks bright for the goal of being energy self sufficient and less dependent on outside energy sources. Perhaps one day, as alternate energy technology advances, we will be producing more energy than is necessary for one’s home, and having the ability to put energy BACK into the system for the entire community such as Liberty to benefit from and becoming truly energy independent.

Gregg Taylerson is the Design Director for Mark Scheurer Architect in Newport Beach, Calif. He may be reached at greggt@msa-arch.com.